Shell Programming and Scripting

abc.123@domain.com,abc.123@domain.com,abc.123@domain.com

or

abc.123@domain.com
abc.123@domain.com
abc.123@domain.com

or 

abc.123@domain.com|abc.123@domain.com|abc.123@domain.com

or even simply,

abc.123@domain.com abc.123@domain.com abc.123@domain.com

 
echo 'this is content' | mailx -s 'subject' $(cat file | tr ',' ' ')
or
echo 'this is content' | mailx -s 'subject' $(cat file | tr '\n' ' ')
or
echo 'this is content' | mailx -s 'subject' $(cat file | tr '|' ' ')
or
echo 'this is content' | mailx -s 'subject' $(cat file)

#!/bin/ksh
sendm()
{
sendto="$1"
/usr/lib/sendmail -t -i <<EOF
Subject: some
From: some
To: $sendto

Maildata

EOF
}

##### main #####
cat somefile | while read addr
do
      sendm "$addr"
done